my $ct = $pgp->encrypt( Filename => 'plain.txt', Recipients => $key, Cipher => 'DES3', SignKeyID => $signkey, SignPassphrase => $GPG_PP ) or die "Encryption failed: ", $pgp->errstr;
if ($ct) {
    open( my $fh, '>', 'encrypted.gpg' );
    print $fh $ct;
    close $fh;
} else {
    #print "gpg failed: $pgp->errstr\n";
    $err = Crypt::OpenPGP->errstr;
    print "gpg failed: $err\n";
}